Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/38257—Contact thermal transfer or sublimation processes characterised by the use of an intermediate receptor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/50—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording
  • B41M5/52—Macromolecular coatings
  • B41M5/5254—Macromolecular coatings characterised by the use of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/02—Dye diffusion thermal transfer printing (D2T2)
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/32—Thermal receivers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/142—Dye mordant
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
  • Y10T428/12063—Nonparticulate metal component
  • Y10T428/12104—Particles discontinuous
  • Y10T428/12111—Separated by nonmetal matrix or binder [e.g., welding electrode, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/31935—Ester, halide or nitrile of addition polymer

Definitions

• the present invention relates to an image-receiving sheet material for a heat-sensitive transfer recording system.
• the present invention also relates to an image forming method comprising transferring a heat-sensitive ink layer containing a coloring material onto an image-receiving sheet material using a thermal head or by irradiating with laser beams to form an image, and then re-transferring the ink image onto a permanent support to form a transfer image.
• the image obtained according to the present invention is of high quality and has excellent printing matter approximation.
• a coloring material is used to form an image.
• a composition containing a coloring material is melted or a coloring material is evaporated or sublimated to form an image on a recording medium such as a paper or a film sheet by adhesion, adsorption or dyeing.
• a heat-sensitive transfer recording system is advantageous in that operation and maintenance are easy, and the apparatus can be down-sized or reduced in cost.
• This heat-sensitive transfer recording system has conventionally been known to include the following two types of systems.
• One type is a heat-fusion type transfer system where a transfer sheet comprising a support having thereon a heat-fusible ink layer is imagewise heated by laser beams or a thermal head to melt-transfer the fusible ink onto an image-receiving sheet for heat-sensitive transfer recording.
• the other type is a sublimation type dye transfer system where an ink sheet for heat-sensitive transfer recording comprising a support having thereon an ink layer containing a heat-diffusible dye (sublimation dye) is used, and the heat-diffusible dye is diffusion-transferred into an image-receiving sheet for heat-sensitive transfer recording.
• a heat-diffusible dye sublimation dye
• the sublimation type dye transfer system is advantageous in that the gradation of an image can be controlled by varying the transfer amount of a dye depending on the change in thermal energy of the thermal head. Therefore, a color image having a continuously variable color density can be obtained by the superimposed recording of cyan, magenta and yellow images.
• this system has the following disadvantages:
• the system may satisfy a limited demand in public use where gradation similar to that of a photograph is desired.
• this technique is not suitable for color proofing, for example, in the printing field where the gradation is reproduced by area gradation alone;
• the sublimation type dye transfer system is not suitable for future high-speed recording applications using a high-resolution thermal head;
• a sublimation type dye transfer material is expensive compared to a heat-fusion type transfer material.
• a heat-fusion type transfer system is advantageous in that its heat-sensitive sensitivity is high compared to a sublimation type dye transfer system, the light resistance of the resulting image is excellent and the material is inexpensive.
• this system has the following disadvantages.
• Such a system is capable of providing a pigment color image having a multiple gradation property only using the area gradation of binary recording JP-A-7-117359 (the term "JP-A" as used herein means an unexamined published Japanese patent application).
• JP-A binary recording JP-A-7-117359
• a high-quality color image or monochrome image having multiple gradation can be achieved by a pigment transfer method using area gradation alone.
• this system can be advantageously used in the card field, the outdoor display field or the meter display field.
• JP-A-52-27642 describes a method where a transfer layer is attached by heating to an intermediate receptor, and then the transfer layer thus attached is transferred to a material such as paper.
• this publication does not mention any improvement in image quality.
• JP-A-63-82786 describes a technique for selecting a resin or wax as well as a butyral resin contained in the heat transfer layer as a component of the coating film other than a butyral resin.
• the resin include a phenol resin, an epoxy resin, a urethane resin, a rosin or polyamide resin and a sulfonamide resin.
• the shadow part vanishes.
• the reproduced gradation property is highly sensitive to changes in temperature and humidity. Another problem is that when the resin is added in a large amount, the surface of the image-receiving layer becomes tacky. This in turn causes an increase in dust flaws or unevenness.
• JP-A-5-254256 describes the formulation of a toner layer comprising a polyamide resin (nylon) binder and a pigment.
• nylon polyamide resin
• the high cohesion of the nylon gives rise to poor dot sharpness and gradation reproducibility, or inferior resistance to changes in temperature and humidity.
• an image-receiving material for heat-sensitive transfer recording that is capable of forming a high-quality multiple gradation color image having good recording sensitivity, dot quality (halftone dot quality) and gradation reproducibility (halftone reproducibility), which image receiving material does not exhibit tackiness, sticking and dust flaws, and wherein the change in recording sensitivity to changes in humidity is reduced and the printed matter approximation is excellent.
• An object of the present invention is to provide an image-receiving sheet for heat-sensitive transfer recording capable of achieving a high-quality multiple gradation color image having good recording sensitivity, dot quality and gradation reproducibility, which image receiving sheet is free from tackiness, sticking and dust flaws and is not sensitive to changes in humidity using a heat-transfer method which provides good performance using only area gradation. Furthermore, an object of this invention is to provide a method for forming a transfer image using the above-described image-receiving sheet material.
• Another object of the present invention is to provide an image-receiving sheet material for heat-transfer recording which can transfer an image to a printing permanent paper and having excellent printed matter approximation such as texture reproduction of the printing permanent paper and gloss of an image. Furthermore, an object of this invention is to provide a method for forming a transfer image using the image-receiving sheet material.
• an image-receiving sheet material for use in forming a transfer image by heat-transferring an ink layer from a transfer material having a heat-transferable ink layer onto an image-receiving sheet material and re-transferring the ink layer from the image-receiving sheet onto a permanent support
• the image-receiving sheet material comprises a support having thereon at least two image-receiving layers, at least one of the image-receiving layers is transferred onto the permanent support and at least the image-receiving layer onto which the ink layer is transferred comprises a modified polyvinyl acetal resin prepared from a polyvinyl acetal resin containing hydroxy groups in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted to a group represented by the following formula (I):
• W represents --CONH--Y 1 , --COO--Y 2 , --Y 3 , --SiY 4 Y 5 Y 6 , SO 2 Y 7 , --CO--Z 1 --COOH or --COCH 2 COMe
• Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y6 and Y7 each represents a monovalent organic group having from 1 to 20 carbon atoms
• Z 1 represents a divalent organic group having from 1 to 20 carbon atoms.
• the support of the image-receiving sheet comprises a flexible, chemically and thermally stable material.
• the material may transmit actinic rays, if desired.
• Specific examples of the material include polyolefins such as a biaxially stretched polyethylene terephthalate film, polyethylene and polypropylene, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, cellulose derivatives such as cellulose acetate, nitrocellulose and cellophane, polyamides, polystyrene, polycarbonates and polyimides.
• a paper laminated with a polyethylene film may also be used.
• biaxially stretched polyethylene terephthalate film having good dimensional stability and transmission, however, the present invention is not limited thereto.
• the thickness of the support for the image-receiving sheet is generally from 30 to 200 ⁇ m.
• At least two image-receiving layers are provided on the support.
• one of the image-receiving layers is a layer in contact with the support (hereinafter referred to as a first image-receiving layer), and the other layer is provided on the first image-receiving layer (hereinafter referred to as a second image-receiving layer).
• the support may be subjected to a surface treatment such as a corona discharge treatment or a glow discharge treatment.
• a surface treatment such as a corona discharge treatment or a glow discharge treatment.
• an undercoat layer may be applied to the support.
• the composition or type of undercoat layer is not particularly limited as long as it increases the adhesive strength between the support and the first image-receiving layer.
• an undercoat layer comprising a silane coupling agent is particularly preferred.
• the first image-receiving layer is described below.
• the first image-receiving layer preferably has a modulus of elasticity of 200 kg.f/cm 2 or less.
• the image-receiving layer is imparted a cushioning property.
• the cushioning property prevents foreign matter such as dust that may be present between a heat-sensitive recording material and the image-receiving sheet material from generating an image defect.
• the first image-receiving layer conforms to irregularities of the paper.
• the second image-receiving layer and the ink layer are adhered to the paper with conforming to the irregularities of the paper, to thereby achieve good adhesion. Therefore, even if the surface of the second image-receiving layer is not subjected to a treatment such as matting after release of the first image-receiving layer, an image having a surface gloss which approximates a printed matter can be obtained.
• the resin composition of the first image-receiving layer include a polyolefin such as polyethylene and polypropylene; an ethylene copolymer such as an ethylene and vinyl acetate copolymer and an ethylene and acrylic ester copolymer; a polyvinyl chloride; a vinyl chloride copolymer such as a vinyl chloride and vinyl acetate copolymer; a polyvinylidene chloride; a vinylidene chloride copolymer; a polymethacrylate; a polyamide resin such as a copolymer of nylon and N-alkoxymethylated nylon; a synthetic rubber; and rubber chloride, and at least one is preferably selected from the above-described organic polymer materials.
• a polyolefin such as polyethylene and polypropylene
• an ethylene copolymer such as an ethylene and vinyl acetate copolymer and an ethylene and acrylic ester copolymer
• a polyvinyl chloride a vinyl chloride
• polyvinyl chloride and the vinyl chloride copolymer (1) each exhibits almost no tackiness at room temperature, (2) each has a relatively low modulus of elasticity to facilitate conformance to irregularities of the transfer image upon heat transferring, (3) it is easy to control the modulus of elasticity due to the availability of an abundance of plasticizers having good compatibility with the resins and (4) it is easy to control the interlayer adhesive strength due to the presence of a hydroxyl group or a carboxyl group in the copolymer components.
• a fluorine-based surface active agent may be added to one or more of the image-receiving layers to reduce the interlayer adhesive strength. At the same time, the wettability between the heat transferable ink layer and the image-receiving layer surface is improved to provide a good dot shape. However, if the addition amount of the fluorine-based surface active agent is excessive, the adhesive strength between the heat transferable ink layer and the image-receiving layer surface is reduced to thereby degrade the dot shape. Accordingly, the releasing agent or the surface active agent is preferably added to the image-receiving layer in an amount of from 0.0001 to 5 wt %, more preferably from 0.001 to 3 wt %. In order to optimize the properties of the coating surface, the surface active agent is preferably added to the image-receiving layer in a small amount.
• a vinyl chloride-based resin When a vinyl chloride-based resin is used as the resin of the image-receiving layer, it is also effective to add an organotin-based stabilizer such as a butyltin-based stabilizer or an octyltin-based stabilizer which is well known in the art as a stabilizer for polyvinyl chloride or a vinyl chloride copolymer.
• organotin-based stabilizer such as a butyltin-based stabilizer or an octyltin-based stabilizer which is well known in the art as a stabilizer for polyvinyl chloride or a vinyl chloride copolymer.
• the thickness of the first image-receiving layer is preferably from 1 to 50 ⁇ m, more preferably from 5 to 30 ⁇ m. Namely, when an image that has been transferred onto the image-receiving sheet material is then transferred to a permanent support, the thickness of the first image-receiving layer must be larger than the irregularities on the surface of the permanent support. Also, the thickness of the first image-receiving layer must be large enough to sufficiently absorb the difference in relief height on portions where four colors are superimposed thereon. Furthermore, the thickness of the first image-receiving layer must be large enough to provide a satisfactory cushioning property.
• the second image-receiving layer provided on the first image-receiving layer is described below.
• the second image-receiving layer is provided so that when the image-receiving sheet is peeled off upon re-transferring to the permanent support, an interlayer release can take place between the first image-receiving layer and the second image-receiving layer. This leaves only the thin second image-receiving layer on the image transferred to the permanent support, to thereby provide an image having a gloss which approximates a practical printed matter due to irregularities of the permanent support and without the need for applying a special matting treatment thereto.
• the second image-receiving layer also improves the flaw resistance of the image. Accordingly, as long as the above-described effects can be provided, the second image-receiving layer may be formed of a laminate comprising two or more layers.
• the second image-receiving layer comprises a modified polyvinyl acetal resin prepared from a polyvinyl acetal resin containing hydroxyl groups in which from 0.1 to 1 equivalent of the hydroxyl groups in the polyvinyl acetal resin have been converted to a group represented by the following formula (I) (hereinafter referred to as a modified polyvinyl acetal resin):
• W represents --CONH--Y 1 , --COO--Y 2 , --Y 3 , --SiY 4 Y 5 Y 6 , SO 2 Y 7 , --CO--Z 1 --COOH or --COCH 2 COMe;
• Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 and Y 7 each represents a monovalent organic group having from 1 to 20 carbon atoms; and
• Z 1 represents a divalent organic group having from 1 to 20 carbon atoms.
• Each of Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 and Y 7 is not particularly limited as long as it is a monovalent organic group having from 1 to 20 carbon atoms. Specific examples thereof include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, amyl, n-hexyl, 2-ethylhexyl, decyl, octadecyl, cyclohexyl, vinyl, allyl, 2-methoxyethyl, 2-ethoxyethyl, 2-methoxypropyl, 2-chloroethyl, trichloroethyl, methoxyethoxyethyl, cyanoethyl, 2-aminocarbonylethyl, benzyl, phenetyl, methoxy
• Z 1 is not particularly limited as long as it is a divalent organic group having from 1 to 20 carbon atoms. Specific examples thereof include ethylene, propylene, vinylene, phenylene, cyclohexylene and cyclohexelene. Furthermore, the divalent organic group may be substituted by a halogen atom, an alkoxy group, a cyano group, a nitro group, an ester group or an acyl group.
• a polyvinyl acetal resin containing hydroxyl groups which have been converted in whole or part into another functional group for use in a heat transfer material as an adduct of a polyvinyl acetal resin and an isocyanate is described, for example, in JP-A-61-14983, JP-A-61-14991, JP-A-61-14992 and JP-A-62-259889.
• the isocyanates described therein are polyfunctional isocyanates. Therefore, the resin described therein differs from the polyvinyl acetal resin of this invention resin modified by the group represented by formula (I). Another difference is that the resin in the above publications is provided on the surface of a support which does not have a heat transfer layer.
• JP-A-61-211094 describes the use of the reaction product of a butyral resin with a crosslinking agent. However, this is different from the resin converted to the group represented by formula (I) of the present invention. Furthermore, the resin in this publication is used as the resin of an ink layer in contrast to the present invention.
• the modified polyvinyl acetal resin of the present invention can be synthesized by subjecting a polyvinyl acetal resin to a polymer reaction in an appropriate solvent with a compound having a suitable functional group and, if desired, in the presence of a reaction catalyst.
• the polyvinyl acetal resin is a resin obtained by acetalizing, for example, a polyvinyl alcohol with at least one aldehyde, and specific examples thereof include copolymer acetals such as polyvinyl acetal, polyvinyl formal, polyvinyl butyral, a partially formalated polyvinyl butyral and polyvinyl butyral acetal.
• These polyvinyl acetal resin generally contains a monomer unit other than the vinyl acetal unit. Specifically, it generally contains therein a vinyl alcohol unit, which remains after the acetalization reaction, generally in an amount of 5 to 40% by weight, and a vinyl acetate unit, which remains after the preparation of the polyvinyl alcohol from polyvinyl acetate by hydrolysis, generally in an amount of not less than 20%.
• the polyvinyl acetal resin is commercially available, and examples thereof include Denkabutyral #2000L, #3000-1, #3000-K, #4000-1, #5000-A, #6000-C Denkaformal #20, #100, #200 (all produced by Denki Kagaku Kogyo K.K.), S-LEK B Series BL-1, BL-2, BL-S, BM-1, BM-2, BH-1, BX-1, BX-10, BL-1, BL-SH, BX-L and S-LEK K Series KS-10 (all produced by Sekisui Chemical Co., Ltd.).
• the polyvinyl acetal resin has an acetalization degree of preferably from about 50 to 85 mol %, more preferably from about 60 to 80 mol %. If the acetalization degree is less than 50 mol %, the solubility of the raw material resin is poor, whereas it is theoretically difficult to synthesize resins having an acetalization degree exceeding 85 mol %.
• the polymerization degree is preferably from about 50 to 2,000, more preferably from 100 to 1,000. Resins having a polymerization degree of less than 50 are difficult to synthesize, whereas those having a polymerization degree exceeding 2,000 have poor solubility.
• solvents examples include acetone, methyl ethyl ketone, tetrahydrofuran, N,N-dimethylformamido, N,N-dimethylacetamido, chloroform, ethyl acetate, methoxypropyl acetate, diethyl ether and dioxane.
• a method for synthesizing the modified polyvinyl acetal resin of the present invention is described below for various types of functional group.
• the modified polyvinyl acetal resin in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted into a urethane group can be obtained, for example, by the addition reaction of a polyvinyl acetal with a monofunctional isocyanate.
• the monofunctional isocyanate examples include ethyl isocyanate, n-propyl isocyanate, i-propyl isocyanate, butyl isocyanate, octadecyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, 3-i-propenylcumyl isocyanate, 4-methoxyphenyl isocyanate, 2-fluorophenyl isocyanate, m-tolyl isocyanate, p-tolyl isocyanate, 2-trifluoromethylphenyl isocyanate, 1-naphthyl isocyanate and ⁇ -methylbenzyl isocyanate.
• a tin catalyst such as dibutyltin diacetate is effective.
• the reaction temperature is preferably from room temperature to about 80° C.
• the modified polyvinyl acetal resin of the present invention in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted into a carbonate group (--OCOO--Y 2 ) can be obtained, for example, by the reaction of a polyvinyl acetal resin with a haloformate.
• haloformate examples include methyl chloroformate, ethyl chloroformate, allyl chloroformate, n-propyl chloroformate, butyl chloroformate, amyl chloroformate, hexyl chloroformate, 2-ethylhexyl chloroformate, 2-chloroethyl chloroformate, 2-methoxyethyl chloroformate, phenyl chloroformate and 2-naphthyl chloroformate.
• a base such as triethylamine, pyridine or sodium hydroxide is preferably added to the reaction mixture.
• the reaction temperature is preferably from 0° to about 40° C.
• the modified polyvinyl acetal resin of the present invention in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted into an ether group (--OY 3 ) can be obtained, for example, by the reaction of a polyvinyl acetal resin or a metal alcoholate of the resin with an organic halide.
• organic halide include methyl iodide, ethyl iodide, benzyl bromide and benzyl chloride.
• the reaction temperature is preferably from room temperature to about 120° C.
• This resin can also be obtained by the addition reaction of a polyvinyl acetal resin with an ⁇ , ⁇ -unsaturated compound such as acrylonitrile or with an epoxy compound.
• a polyvinyl acetal resin with an ⁇ , ⁇ -unsaturated compound such as acrylonitrile or with an epoxy compound.
• the use of sodium hydroxide, potassium hydroxide, triethylamine or triethylbenzyl ammonium chloride is effective.
• the reaction temperature is preferably from room temperature to about 100° C.
• the modified polyvinyl acetal resin of the present invention in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted into a silyl ether group (--OSiY 4 Y 5 Y 6 ) can be obtained, for example, by the dehydrohalogenation reaction of a polyvinyl acetal resin with a silane halogenide.
• the silane halogenide include trimethylsilyl chloride and t-butyldimethylsilyl chloride.
• the use of sodium hydroxide, potassium hydroxide, triethylamine or pyridine is preferred.
• the reaction temperature is preferably from 0° to about 40° C.
• the modified polyvinyl acetal resin of the present invention in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinylacetal resin have been converted into a dibasic acid half ester group (--OCO--Z 1 --COOH) can be obtained, for example, by the addition reaction of a polyvinyl acetal resin with a dibasic acid anhydride.
• the dibasic acid anhydride include succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, cyclohexanedicarboxylic anhydride and cyclohexenedicarboxylic anhydride.
• trimethylamine, pyridine or dimethylaminopyridine is preferably used.
• the reaction temperature is preferably from room temperature to about 100° C.
• the modified polyvinyl acetal resin of the present invention in which from 0.1 to 1 equivalent of the hydroxyl groups of the polyvinyl acetal resin have been converted into an acetoacetate group (--OCOCH 2 COMe) can be obtained, for example, by the addition reaction of a polyvinyl acetal resin with a diketene. In this reaction, sodium acetate or imidazole is preferably used.
• the reaction temperature is preferably from room temperature to about 80° C.
• the modification ratio of the modified polyvinyl acetal resin of the present invention is preferably from 0.1 to 1 equivalents, more preferably from 0.2 to 1 equivalents.
• one equivalent represents the entire hydroxyl group content of the polyvinyl acetal resin raw material. If it is less than 0.1 equivalents, the change in recording sensitivity to changes in humidity is large. In these reactions, it is also possible to use the reaction reagent in an amount of one or more equivalents based on the hydroxyl group content of the polyvinyl acetal resin raw material so as to effectively proceed with the reaction.
• the excess reagent may remain within a range such that there is no adverse effect on performance, or the excess reagent may be removed by purification, if desired.
• the polyvinyl acetal resin usually contains some water, a reaction product with water may be present. A reaction product with water may remain within a range such that there is no adverse effect on performance, or the reaction product with water may be removed by purification, if desired. Or, dehydration treatment may be applied during or before the reaction.
• the modified polyvinyl acetal resin of this invention may be used alone or in a combination of two or more kinds of modified polyvinyl acetal resins.
• the content of the modified polyvinyl acetal resin is based on the total solid content of the second image-receiving layer, and is preferably 40 wt % or more, more preferably 50 wt % or more, still more preferably 60 wt % or more.
• a high molecular weight compound having a repeating unit represented by the following formula (II) and/or formula (II) is preferably used in combination with the modified polyvinyl acetal resin of this invention: ##STR1## wherein R 1 represents a hydrogen atom or a methyl group, A represents a substituent having an amide bond or a nitrogen-containing heterocyclic ring, R 4 represents a hydrogen atom or a methyl group, R 6 , R 7 and R 8 , which may the same or different, each represents an alkyl group having from 1 to 25 carbon atoms, an aralkyl group having from 7 to 25 carbon atoms or an aryl group having from 6 to 25 carbon atoms (the alkyl group, the aralkyl group or the aryl group may be substituted by a hydroxy group, an alkoxy group having from 1 to 6 carbon atoms, a halogen, a cyano group or a combination of two or more of these groups, either directly of via an
• the high molecular weight compound having a repeating unit represented by formula (II) and/or (III) can be obtained by polymerizing a monomer represented by the following formula (IV) and/or (V) in a manner known to those of ordinary skill in an appropriate solvent, or using no solvent but in the presence of a polymerization initiator, or by copolymerizing the monomers represented by formulae (IV) and/or (V) with other monomers: ##STR2## (wherein R 1 , A, R 4 , R 6 , R 7 , R 8 and X each has the same meaning as defined in formulae (II) and (III)).
• a of formula (IV) is a substituent having an amide bond
• A represents CONHR 2 or CONR 2 R 3 , wherein R 2 and R 3 each independently represents a hydrogen atom, an alkyl group having from 1 to 18 carbon atoms or an aryl group having from 6 to 20 carbon atoms (the alkyl group or the aryl group may be substituted with at least one of a hydroxyl group, an alkoxy group having from 1 to 6 carbon atoms, a halogen and a cyano group or a combination of two or more of these groups) or R 2 and R 3 may be combined to form an alkylene or aralkylene having from to 20 carbon atoms (the alkylene and the aralkylene each may be branched or may have an ether bond, --OCO--, --COO-- or a combination of two or more of these groups).
• A represents an imidazole, a pyrrolidone, a pyridine or a carbazole, which groups each may be substituted by an alkyl group having from 1 to 5 carbon atoms, an aryl group having from 6 to 10 carbon atoms, a halogen, a cyano group or a combination of two or more of these groups.
• a of formula (IV) when A of formula (IV) is a substituent having an amido group, A represents CONHR 2 or CONR 2 R 3 , wherein R 2 represents a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms or an aryl group having from 6 to 15 carbon atoms (the alkyl group or the aryl group may be substituted by a hydroxyl group or an alkoxy group having from 1 to 6 carbon atoms), and when A is a nitrogen-containing heterocyclic ring, A represents an imidazole or a triazole, which groups each may be substituted by an alkyl group having from 1 to 5 carbon atoms or an aryl group having from 6 to 10 carbon atoms.
• the compound represented by formula (IV) include (meth)acrylamido, N-alkyl(meth)acrylamido (examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a heptyl group, an octyl group, an ethylhexyl group, a cyclohexyl group, a hydroxyethyl group and a benzyl group), N-aryl(meth)acrylamido (examples of the aryl group include a phenyl group, a tolyl group, a nitrophenyl group, a naphthyl group and a hydroxyphenyl group), an N,N-dialkyl(meth)acrylamido (examples of the alkyl group include a methyl group, an ethyl group, a buty
• R 4 represents a hydrogen atom or a methyl group
• R 6 , R 7 and R 8 which may be the same or different, each represents an alkyl group having from 1 to 25 carbon atoms, an aralkyl group having from 7 to 25 carbon atoms, an aryl group having from 6 to 25 carbon atoms (the alkyl group, the aralkyl group or the aryl group may be substituted by a hydroxy group, an alkoxy group having from 1 to 6 carbon atoms, a halogen, a cyano group or a combination of two or more of these groups either directly or via an ether bond, --OCO--, --COO-- or a combination of two or more of these groups); and X represents Cl, Br or I.
• R 4 represents a hydrogen atom or a methyl group
• R 6 , R 7 and R 8 which may be the same or different, each represents an alkyl group having from 1 to 20 carbon atoms, an aralkyl group having from 7 to 18 carbon atoms or an aryl group having from 6 to 20 carbon atoms (the alkyl group, the aralkyl group or the aryl group may be substituted by an alkoxy group having from 1 to 6 carbon atoms, a halogen, a cyano group or a combination of two or more of these groups either directly or via an ether bond, --OCO--, --COO-- or a combination of two or more of these groups) and X represents Cl, Br or I.
• the compound represented by formula (V) include N,N,N-(trialkyl)-N-(styrylmethyl)-ammonium chloride, N,N,N-(trialkyl)-N-(styrylmethyl)-ammonium bromide, N,N,N-(trialkyl)-N-(styrylmethyl)-ammonium iodide (examples of the alkyl include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a heptyl group, a hexyl group, an octyl group, an isooctyl group, a dodecyl group, an ethylhexyl group and a cyclohexyl group), N,N-(dimethyl)-N-(dodecyl)-N-(styrylmethyl)-ammonium chloride,
• monomers copolymerizable with the monomer represented by formula (IV) and/or formula (V) include compounds having a polymerizable unsaturated bond selected from (meth)acrylic esters, (meth)acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes and crotonic acid esters.
• the compound include (meth)acrylates such as an alkyl (meth)acrylate or substituted alkyl (meth)acrylate (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, ethylhexyl (meth)acrylate, octyl (meth)acrylate, t-octyl (meth)acrylate, chloroethyl (meth)acrylate, allyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2,2-dimethyl-3-hydroxypropyl (meth)acrylate, 5-hydroxy
• Preferred specific examples of the polymer having a repeating unit represented by formula (II) and/or formula (III) include an N,N-dimethylacrylamido/butyl (meth)acrylate copolymer, an N,N-dimethyl (meth)acrylamido/2-ethylhexyl (meth)acrylate copolymer, an N,N-dimethyl (meth)-acrylamido/hexyl (meth)acrylate copolymer, an N-butyl(meth)acrylamido/butyl (meth)acrylate copolymer, an N-butyl(meth)acrylamido/2-ethylhexyl (meth)acrylate copolymer, an N-butyl(meth)acrylamido/hexyl (meth)acrylate copolymer, a (meth)acryloylmorpholine/butyl (meth)acrylate copolymer, a (meth)
• the content of the repeating unit represented by the formula (II) and/or formula (III) of the high molecular weight compound is preferably from 5 to 100 mol %, more preferably from 10 to 100 mol %. If the content of the repeating unit represented by the formula (II) and/or formula (III) is less than 5 mol %, the image quality is inferior.
• the weight average molecular weight is preferably from 1,000 to 200,000, more preferably from 2,000 to 100,000. If the molecular weight is less than 1,000, production is difficult, whereas if it exceeds 200,000, solubility in a solvent is lowered.
• the high molecular weight compound having a repeating unit represented by formula (II) and/or formula (III) is added to the second image-receiving layer in an amount, based on the total solid content, of preferably from 0 to 50 wt %. If the addition amount exceeds 50 wt %, the second image-receiving layer becomes tacky on the surface thereof and presents difficulty in handling.
• the addition amount is more preferably from 0 to 40 wt %, most preferably from 5 to 40 wt %.
• resins may further be added to the second image-receiving layer, if desired, within a range such that the performance is not adversely affected.
• Various resins may be used in combination and examples thereof include a polyolefin such as polyethylene and polypropylene, an ethylene copolymer such as ethylene/vinyl acetate copolymer, ethylene/acrylate copolymer and ethyl/acrylic acid copolymer, a vinyl chloride copolymer such as polyvinyl chloride and vinyl chloride/vinyl acetate copolymer, a polyvinylidene chloride, a vinylidene chloride copolymer, a styrene copolymer such as polystyrene and styrene/maleate copolymer, a polyalkyl (meth)acrylate (co)polymer, an alkyl (meth)acrylate/(meth)acrylic acid copolymer, a poly(meth
• the coating solvent for coating the second image-receiving layer is a coating solvent which does not dissolve or swell the resin used in the first image-receiving layer so that the first image-receiving layer and the second image-receiving layer are not mixed with each other due to penetration of the coating solvent into the lower layer upon coating.
• a coating solvent which does not dissolve or swell the resin used in the first image-receiving layer so that the first image-receiving layer and the second image-receiving layer are not mixed with each other due to penetration of the coating solvent into the lower layer upon coating.
• an alcohol or aqueous coating solvent is preferably used in the second image-receiving layer.
• the thickness of the second image-receiving layer is preferably approximately from 0.1 to 10 ⁇ m, more preferably from 0.5 to 5 ⁇ m. If the thickness is too large, irregularities present on the surface of the permanent support is obscured, and the gloss is excessively intensified to deteriorate the printed matter approximation.
• the balance of adhesive strength between respective layers is important.
• mixing of materials must be prevented upon coating of layers in a superimposed manner in accordance with the present invention.
• the coating solvent in addition to selection of the coating solvent, it is effective to select materials such that a hydrophilic polymer and an oleophilic polymer or a polar polymer and a nonpolar polymer are used in combination, or to add an adhesion improving agent such as a silane coupling agent, various fluorine or silicone additives capable of providing a releasing effect, a surface active agent or a plasticizer to the first image-receiving layer or the second image-receiving layer.
• an adhesion improving agent such as a silane coupling agent, various fluorine or silicone additives capable of providing a releasing effect, a surface active agent or a plasticizer
• a layer of various releasing agents or lubricants may be provided as an overcoat layer on the second image-receiving layer, that is, on the layer which receives the heat transferable ink layer.
• these agents include a higher fatty acid such as palmitic acid and stearic acid, a fatty acid metal salt such as zinc stearate, a fatty acid ester or a partial saponification product thereof, a fatty acid derivative such as fatty acid amide, a higher alcohol, an ester derivative of a polyhydric alcohol, a wax such as paraffin wax, carnauba wax, montan wax, beeswax, Japan wax and candelilla wax, a cationic surface active agent such as an ammonium salt and a pyridium salt each having a long chained aliphatic group, an anionic or nonionic surface active agent having a long chained aliphatic group and a perfluoro surface active agent, and one or more of these may be selected.
• a higher fatty acid such as palmitic acid and stearic acid
• a fatty acid metal salt such as zinc stearate
• a fatty acid ester or a partial saponification product thereof
• An interlayer may also be provided between the first image-receiving layer and the second image-receiving layer for controlling transferability. Furthermore, a layer intended to improve slipperiness or flaw resistance between image-receiving sheets may be provided on the support opposite the side having the first image-receiving layer and the second image-receiving layer.
• a transfer material comprising a support having thereon an ink layer capable of heat transfer (hereinafter referred to as "heat transfer sheet”) for use in the present invention is described below.
• Various supports known as a support for conventional fusion transfer or sublimation transfer may be used as the support of the heat transfer sheet.
• a polyester film having a thickness of about 5 ⁇ m with the back surface being subjected to a releasing treatment is particularly preferred.
• Examples of the material for use in the support for the heat transfer sheet include polyolefines such as polyethylene and polypropylene, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, cellulose derivatives such as cellulose acetate, nitrocellulose and cellophane, and polyesters such as polyethylene terephthalate, polyethylene naphthalate and a biaxially stretched film thereof.
• polyolefines such as polyethylene and polypropylene
• polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride
• cellulose derivatives such as cellulose acetate, nitrocellulose and cellophane
• polyesters such as polyethylene terephthalate, polyethylene naphthalate and a biaxially stretched film thereof.
• the ink layer of the heat transfer sheet contains a coloring material (predominantly a pigment) and a non-crystalline organic polymer binder material as main components.
• a coloring material predominantly a pigment
• a non-crystalline organic polymer binder material as main components.
• Various known pigments can be used as the pigment, and examples thereof include carbon black, an azo pigment, a phthalocyanine pigment, a quinacridone pigment, a thioindigo pigment, an anthraquinone pigment and an isoindoline pigment. These pigments may be used in combination of two or more thereof, or a known dye may also be added thereto so as to adjust the hue.
• the noncrystalline organic polymer binder material preferably has a softening point of from 50° to 150° C., and examples thereof include a butyral resin, a polyamido resin, a polyethyleneimine resin, a sulfonamide resin, a polyester polyol resin, a petroleum resin, styrene or a derivative thereof such as vinyltoluene, ⁇ -methylstyrene, 2-methylstyrene, chlorostyrene, vinylbenzoic acid, sodium vinylbenzene sulfonate and aminostyrene and a homopolymer or a copolymer of these derivatives or substitution products, a methacrylic acid or a methacrylate such as methyl methacrylate, ethyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate, an acrylic acid or acrylate such as methyl acrylate, ethyl acrylate, butyl acrylate and ⁇ -
• a butyral resin and a styrene/maleic acid half ester resin in view of dispersibility which is one of features of the present invention.
• This resin preferably has a softening point of from 50° to 150° C. If the softening point exceeds 150° C., the heat recording sensitivity is low, whereas if it is less than 50° C., the ink layer is inferior in resistance to adhesion.
• the ink layer may contain a releasing agent or a softening agent in an amount of from 1 to 20 wt % based on the total weight of the ink layer so as to improve releasability of the ink layer from the support or to improve heat sensitivity upon heat printing.
• these agents include a higher fatty acid such as palmitic acid and stearic acid, a fatty acid metal salt such as zinc stearate, a fatty acid ester or a partial saponification product thereof, a fatty acid derivative such as a fatty acid amido, a higher alcohol, an ester derivative of a polyhydric alcohol, a wax such as paraffin wax, carnauba wax, montan wax, beeswax, Japan wax and candelilla wax, a low molecular weight polyolefin such as polyethylene, polypropylene and polybutylene each having a viscosity average molecular weight of from about 1,000 to about 10,000, a low molecular weight copolymer of an olefin or an ⁇ -olefin with an organic acid such as maleic anhydride, acrylic acid or methacrylic acid or with vinyl acetate, a low molecular weight polyolefin oxide, a polyolefin halide, a methoxymethyl
• the heat transferable ink layer preferably has an optical density such that the reflection density after heat transferred to a white support is 1.0 or more for obtaining an image having excellent printed matter approximation.
• the thickness of the ink layer is preferably from 0.2 to 1.0 ⁇ m. If the thickness of the ink layer exceeds 1.0 ⁇ m, in reproducing gradation by area gradation only, the shadow part easily vanishes or the highlight part is prone to jumping, which results in inferior reproduction of gradation. On the other hand, if it is less than 0.2 ⁇ m, it is difficult to achieve the desired density.
• the ink layer preferably comprises from 30 to 70 parts by weight of a pigment, from 25 to 60 parts by weight of a noncrystalline organic polymer binder material per 100 parts by weight of the ink layer.
• the total amounts of the releasing substance and the softening agent which added, if desired, is preferably from 1 to 15 parts by weight per 100 parts by weight of the ink layer.
• the pigment ratio is less than 30 parts by weight, it is difficult to achieve the desired density with the above-described layer thickness.
• 70% of the pigment preferably have a particle size of 1.0 ⁇ m or less. If the particle size is larger than 1.0 ⁇ m, the transparency may be impaired upon reproduction of colors on the part where respective colors are superimposed. In addition, it is difficult to satisfy the layer thickness and the desired density at the same time.
• the pigment may be dispersed in the noncrystalline organic polymer binder material by adding thereto an appropriate solvent using various dispersion means commonly used in the paint field including a ball mill.
• the heat transferable ink layer comprises as main components a pigment and a noncrystalline organic polymer binder material, has a high pigment ratio as compared with a conventional wax-fusion type ink layer and does not undergo reduction in viscosity upon heat transferring to from 10 2 to 10 3 cps as compared with commonly used fusion type ink layers. Rather, the heat transferable ink layer has a viscosity of at least 10 4 cps or more at a temperature of 150° C.
• the present invention provides a thin film releasing development type image formation technique using the heat adhesion property of the receiving sheet or, in the case of forming a color image, the heat adhesion property between the receiving sheet and the ink layer.
• this technique can achieve reproduction of gradation over a wide range from a shadow part to a highlight part, good edge sharpness and 100% transfer of an image while maintaining high resolution.
• a small character of 4 point and the solid part can have a uniform density.
• modified polyvinyl acetal resins (Resin Nos. 2 to 13) were obtained in the same manner as in Synthesis Example 1.
• reaction solution was poured into 3 l of water containing 9 ml of hydrochloric acid, purified by reprecipitation, further washed with water and dried to obtain 43.9 parts of a resin where the hydroxyl group of the polyvinyl butyral had been converted into a benzyl ether group (Resin No. 19).
• Coating solutions for the first image-receiving layer and the second image-receiving layer were prepared each having the following composition.
• the above-described coating solution for the first image-receiving layer was coated on a 100 ⁇ m-thick polyethylene terephthalate (PET) film support by means of a rotary coater (wheeler) at 300 rpm and dried in an oven at 100° C. for 2 minutes.
• the resulting first image-receiving layer had a thickness of 20 ⁇ m.
• the above-described coating solution for the second image-receiving layer was coated by means of a rotary coater (wheeler) at 200 rpm and dried in an oven at 100° C. for 2 minutes.
• the resulting second image-receiving layer had a thickness of 2 ⁇ m.
• the cyan heat transfer sheet was superimposed on the image-receiving sheet material, and printing was conducted using a thermal head recording apparatus (experimental model) according to a secondary scanning division method.
• a thermal head recording apparatus experimental model
• a head of 75 ⁇ m ⁇ 50 ⁇ m is driven into microfeeding in the 50 ⁇ m direction and subjected to on-off operation at a 3 ⁇ m pitch to effect multistage modulation of area gradation only.
• the cyan heat transfer sheet was peeled off to form an image composed of area gradation only on the image-receiving sheet material.
• magenta heat transfer sheet was superimposed on the image-receiving sheet material on which the cyan image was formed, positioned and printed in the same manner as described above, and the heat transfer sheet was peeled off to obtain a magenta image on the image-receiving sheet material.
• a yellow image was formed in the same manner as described above, and a color image composed of area gradation only was formed on the image-receiving sheet material.
• the image-receiving sheet material having formed thereon a color image was superimposed on an art paper, a heat roller at 130° C.
• the density of a 4P character was measured using a microdensitometer, and the density thus determined was equal to the density of a solid part.
• the gradation reproduction was observed in the range of from 5 to 95% there were no apparent flaws due to dust and the dot shape was good.
• the transferred second image receiving layer conformed to irregularities of the paper. As a result, the surface of the product was duly matted to give the image a surface gloss very approximate to that of a printed matter.
• Image-receiving sheets were prepared in the same manner as in Example 1, except for changing the composition of the modified polyvinyl butyral resin (Resin No. 1) and the high molecular weight compound (Resin No. 24) of Synthesis Example 1 in Example 1, as shown in Table 3. Using each of these image-receiving sheets, a color image was formed in the same manner as in Example 1, and then the image was evaluated. The evaluation results are shown in Table 4.
• Example 2 An image was formed as in Example 1 at 25° C. under low humidity conditions of 20% relative humidity. A printing energy giving a dot percent of 50% under the above-described conditions was determined. Using this resulting printing energy, image printing was conducted at 25° C. under high humidity conditions of 80% relative humidity, and the dot percent under the higher humidity conditions was measured. Images having a dot percent of 68% or less (3% or less as a rate of change per 10% changes in humidity) were evaluated as being good, and those having a lower dot percent were evaluated as being bad.
• a styrene-butadiene copolymer (thickness: 0.5 ⁇ m) and gelatin (thickness: 0.1 ⁇ m) were provided in this order as undercoat layers on a polyethylene terephthalate film having a thickness of 75 ⁇ m to prepare a support for the heat transfer sheet.
• the above-described coating solution for the light-heat conversion layer was coated over a period of 1 minute using a rotary coater (wheeler), and the coating was dried in an oven at 100° C. for 2 minutes to form a light-heat conventions layer (thickness determined by a stylus type film thickness gauge: 0.3 ⁇ m, light absorbance at a wavelength of 488 nm: 90%).
• the same sample was observed in cross-section by a scanning type electron microscope, and the average film thickness was found to be 0.3 ⁇ m.
• the coating solution for the heat releasing layer prepared above was coated over a period of 1 minute using a rotary coater (wheeler), and the coating was dried in an oven at 100° C. for 2 minutes.
• the coating solution for the heat releasing layer was also coated on a polyester film (thickness: 100 ⁇ m) having a smooth surface and dried under the same conditions. The film thickness at this time was measured by a stylus type film thickness gauge and found to be 0.1 ⁇ m.
• the coating solution for the image forming layer prepared above was coated over a period of 1 minute using a rotary coater (wheeler). The coating was dried in an oven at 100° C. for 2 minutes to laminate an image-forming layer having an optical density as determined by a Macbeth densitometer of 0.7 to thereby produce a heat transfer sheet.
• the above-described coating solution for the image forming layer was also coated on a polyester film (thickness: 100 ⁇ m) under the same conditions and dried, and the film thickness was measured and found to be 0.3 ⁇ m.
• the film thickness of the magenta image forming layer of the heat transfer sheet was measured by a cross section observation method, and the average thereof was nearly 0.3 ⁇ m.
• An image-receiving sheet material was prepared in the same manner as in Example 1.
• the heat transfer sheet and the image-receiving sheet material prepared as above were passed through heat rollers each having a surface temperature of 70° C. under a pressure of 4.5 kg/cm 2 and at a speed of 200 cm/min to produce a laminate.
• the image receiving layer and the heat transferable ink layer came into substantially uniform contact with each other.
• the laminating pressure was measured using a pressure-sensitive color forming material (prescale) for measuring pressure produced by Fuji Photo Film Co., Ltd. by passing the material through rollers at room temperature.
• the thus-obtained laminate was wound around a rotary drum having an opened suction hole for vacuum adsorption so that the heat transfer sheet support and the image-receiving sheet material support were put into contact with a laser beam entering surface and the rotary drum surface, respectively, and fixed in place under vacuum.
• Semiconductor laser beams having a wavelength of 830 nm were focused on the light-heat conversion layer as a spot of 8 ⁇ m, and the laser beams were modulated according to the recording image while moving (secondary scanning) in the direction perpendicular to the rotating direction (main scanning direction) of the rotary drum.
• the conditions for the laser recording were as follows.
• the laminate was removed from the drum and the image-receiving sheet material and the heat transfer sheet were manually peeled apart. As a result, it was clearly observed that the image forming layer only at the part irradiated by laser beams was transferred to the image-receiving layer. Furthermore, when the transferred image was observed through an optical microscope, dots of 200 lines/inch were reproduced in a range of from 3 to 98%. The dot shape was also good.
• an image-receiving sheet material By using an image-receiving sheet material, a transfer image formation method and a laminate according to the present invention, an image is provided which has good recording sensitivity, dot quality (halftone dot shape) and gradation reproducibility (halftone dot reproducibility). Furthermore, the material is not tacky, and is free from sticking and dust flaws. Moreover, the recording sensitivity to changes in humidity is reduced, and good printed matter approximation is obtained.

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